Proximity coupling interconnect packaging systems and methods

ABSTRACT

Proximity coupling interconnect packaging systems and methods. A semiconductor package assembly comprises a substrate, a first semiconductor die disposed adjacent the substrate, and a second semiconductor die stacked over the first semiconductor die. There is at least one proximity coupling interconnect between the first semiconductor die and the second semiconductor die, the proximity coupling interconnect comprising a first conductive pad on the first coupling face on the first semiconductor die and a second conductive pad on a second coupling face of the second semiconductor die, the second conductive pad spaced apart from the first conductive pad by a gap distance and aligned with the first conductive pad. An electrical connector is positioned laterally apart from the proximity coupling interconnect and extends between the second semiconductor die and the substrate, the position of the electrical connector defining the alignment of the first conductive pad and the second conductive pad.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/046,859, filed Jul. 26, 2018; which is a continuation of U.S. patentapplication Ser. No. 15/422,230, filed Feb. 1, 2017, now U.S. Pat. No.10,062,678; which is a divisional of U.S. patent application Ser. No.14/556,450, filed Dec. 1, 2014, now U.S. Pat. No. 9,595,513; each ofwhich is incorporated herein by reference.

TECHNICAL FIELD

The disclosed embodiments relate to semiconductor devices and moreparticularly to proximity coupling interconnects between semiconductordies and packages therefor.

BACKGROUND

In semiconductor processing, interconnects are used to provideelectrical connection between adjacent semiconductor dies. Forvertically stacked semiconductor dies, through-silicon vias (TSV) areoften used. Such TSVs on adjacent semiconductor dies are typicallyelectrically connected to each other using direct physical coupling inwhich the bond pads of one die are directly bonded to the bond pads ofthe other.

Direct bonding of interconnects requires relatively large bond pads(e.g., 45×45 microns or larger) and also results in relatively highpower consumption and current drop. Proximity coupling, which is analternative to direct bonding, involves positioning the conductive padsof one die adjacent to, but physically separated from, the conductivepads of another die. In proximity coupling, there is a gap that is notfilled with a conductive material between the adjacent pairs of bondpads. Proximity coupling interconnects rely on either magnetic flux(inductive coupling) or electric field (capacitive coupling) to serve asthe medium through which signals are transmitted between the adjacentconductive pads. Proximity coupling can achieve lower power consumptionand lower current drop than direct physical coupling. Additionally,proximity coupling can be utilized with significantly smaller conductivepads (e.g., on the order of 5×5 microns, 20×20 microns, or larger).However, the use of smaller conductive pads for proximity coupling alsorequires more precise alignment between adjacent conductive pads.Additionally, the vertical distance between the adjacent conductive padsmust be controlled precisely to achieve effective coupling. Whileproximity coupling interconnects have been demonstrated in principle,there remains a need to develop practical methods to incorporateproximity coupling interconnects into packaging systems and methodsutilizing standard semiconductor processing techniques.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a top plan view illustrating a portion of a semiconductor dieassembly in accordance with embodiments of the present technology.

FIG. 1B is a cross-sectional view of the semiconductor die assemblyshown in FIG. 1A.

FIG. 1C is an enlarged detail view of a portion of the semiconductor dieassembly shown in FIG. 1B.

FIGS. 2A-2G are cross-sectional views illustrating a method ofmanufacturing a semiconductor die assembly in accordance withembodiments of the present technology.

FIG. 3 illustrates a top plan view of another embodiment of asemiconductor die assembly in accordance with the present technology.

FIG. 4 illustrates a cross-sectional view of another embodiment of asemiconductor die assembly in accordance with the present technology.

FIG. 5 is a schematic view of a system that includes a semiconductor dieassembly configured in accordance with embodiments of the presenttechnology.

DETAILED DESCRIPTION

Specific details of several embodiments of semiconductor die assemblieshaving proximity coupling interconnects and associated systems andmethods are described below. The term “semiconductor die” generallyrefers to a die having integrated circuits or components, data storageelements, processing components, and/or other features manufactured onsemiconductor substrates. For example, semiconductor dies can includeintegrated circuit memory and/or logic circuitry. A person skilled inthe relevant art will also understand that the technology may haveadditional embodiments, and that the technology may be practiced withoutseveral of the details of the embodiments described below with referenceto FIGS. 1A-5.

As used herein, the terms “vertical,” “lateral,” “upper,” and “lower”can refer to relative directions or positions of features in thesemiconductor die assemblies in view of the orientation shown in theFigures. For example, “upper” or “uppermost” can refer to a featurepositioned closer to the top of a page than another feature. Theseterms, however, should be construed broadly to include semiconductordevices having other orientations, such as inverted or inclinedorientations where top/bottom, over/under, above/below, up/down andleft/right can be interchanged depending on the orientation.

FIGS. 1A and 1B illustrate top plan and cross-sectional views,respectively, of a semiconductor die assembly 100 in accordance with thepresent technology. FIG. 1C illustrates an enlarged detail view of aportion of the assembly 100 shown in FIG. 1B. Referring to FIGS. 1A-Ctogether the assembly 100 includes a first die 109 (e.g., a memory die)and a spacer 117 disposed over a substrate 101. The substrate 101 has anupper surface 103 and a lower surface 105. The substrate 101 can includea plurality of solder bumps 107 disposed on the lower surface 105 formounting the assembly 100 to a printed circuit board or other chip (notshown) and a plurality of alignment pads 133 on the upper surface 103.As explained in more detail below, the alignment pads 133 can beelectrically conductive bond pads that also provide additional alignmentfeatures for the components on the substrate 101.

The first die 109 is disposed on the upper surface 103 of the substrate101 and can be attached to the substrate 101 via conventional die attachmethods such as adhesive paste, tape, or films. The first die 109includes a coupling face 111 that faces away from the substrate 101, anda passivation layer 113 is disposed over the coupling face 111 of thefirst die 109. The passivation layer 113 can include polyimide, siliconnitride, silicon dioxide, titanium dioxide, aluminum oxide, or othersuitable materials. The first die 109 can be electrically coupled to acontact pad 114 on the substrate 101 via a wirebond 115. In someembodiments, the first die 109 can be electrically coupled to thesubstrate 101 via through-silicon vias or other techniques.

The spacer 117 is disposed at a location on the upper surface 103 of thesubstrate 101 that is spaced laterally apart from the first die 109. Thespacer 117 can be attached to the substrate 101 via conventional dieattach methods such as adhesive paste, tape, or films. The spacer 117,for example, can be a dummy die or other type of die. The spacer 117includes a coupling face 119 that faces away from the substrate 101, anda passivation layer 121 is disposed over the coupling face 119 of thespacer 117. The passivation layer 121 can include polyimide, siliconnitride, silicon dioxide, titanium dioxide, aluminum oxide, or othersuitable dielectric materials. In the illustrated embodiment, the firstdie 109 has the same thickness as the spacer 117, and the passivationlayer 113 on the first die 109 has the same thickness as the passivationlayer 121 on the spacer 117. In some embodiments, the passivation layer121 can be omitted from the spacer 117, in which case the spacer 117 maybe configured to have an overall thickness equivalent to the thicknessof the first die 109 and the passivation layer 113. In some embodiments,the thickness of the passivation layer 121 on the spacer 117 can have adifferent thickness than the passivation layer 113 on the first die 109.

The assembly 100 can further include a second die 123 (e.g., a logicdie) disposed over both the first die 109 and the spacer 117. The seconddie 123 includes a coupling face 125 that faces the first die 109 andthe spacer 117 as well as the substrate 101, and another passivationlayer 127 is disposed on the coupling face 125 of the second die 123.The passivation layer 127 can include polyimide, silicon nitride,silicon dioxide, titanium dioxide, aluminum oxide, or other suitabledielectric materials. The second die 123 can further include a pluralityof bond pads 129 disposed on the coupling face 125. In the illustratedembodiment, the passivation layer 127 may have openings that expose thebond pads 129.

The assembly 100 can further include connectors 131 that extend betweenthe logic die bond pads 129 and corresponding alignment pads 133disposed on the upper surface 103 of the substrate 101. The connectors131 can be electrically conductive, and each connector 131 may be fusedand bonded with one of the bond pads 129 on the second die 123 as wellas fused and bonded with one of the alignment pads 133 on the substrate101. For example, the connectors 131 can be large solder elements. Inthe illustrated embodiment, two connectors 131 are illustrated. However,in various embodiments an array of connectors 131 corresponding to thenumber of required electrical connections can be used. The alignmentpads 133 on the substrate 101 are disposed laterally between the firstdie 109 and the spacer 117. The alignment pads 133 can also beelectrically connected to traces or other conductive lines in thesubstrate 101. The alignment pads 133, therefore, can act as regularbond pads for electrically coupling the second die 123 to the substrate101. In some embodiments, the dimensions of the connectors 131 and/orthe dimensions of the bond pads 129 can define the spacing between thesubstrate 101 and the second die 123. In some embodiments, an underfillmaterial can be disposed between the substrate 101 and the second die123 so as to substantially surround the connectors 131.

In the illustrated embodiment, the first die 109 and the spacer 117 aredisposed on the substrate 101 with a second die 123 disposed over thefirst die 109 and the spacer 117. In some embodiments, the varioussemiconductor dies can take different forms. For example, a logic diemay be disposed on the substrate and a memory die may be disposed overthe logic die. In other embodiments, different semiconductor dies may beused, and need not be limited to memory dies, logic dies, and/orspacers.

The assembly 100 further includes a plurality of proximity couplinginterconnects 135 (FIG. 1A) that each have a first conductive pad 137disposed on the coupling face 111 of the first die 109, a secondconductive pad 139 disposed on the coupling face 125 of the second die123, and a gap 141 (e.g., void or other space) between the firstconductive pad 137 and the second conductive pad 139. The firstconductive pad 137 is exposed through the passivation layer 113 on thefirst die 109, and the second conductive pad 139 is exposed through thepassivation layer 127 on the second die 123. In some embodiments, thefirst conductive pad 137 and the second conductive pad 139 can each besized between about 5 microns by about 5 microns to about 25 microns by25 microns. In some embodiments, the first conductive pad 137 and thesecond conductive pad 139 can each be sized at less than about 5 micronsby about 5 microns, or greater than about 25 microns by about 25microns. In the embodiment shown in FIG. 1A, five proximity couplinginterconnects 135 are illustrated for clarity. However, in variousembodiments an array of up to 100, 1000, or more proximity couplinginterconnects can be provided for communication between onesemiconductor die and another.

The gap 141 between the first conductive pad 137 and the secondconductive pad 139 can have a height H selected to provide theappropriate electrical properties for the proximity couplinginterconnect 135. The gap 141 may be an empty void, or it can be filledwith a gas, a solid, or a dielectric material or another material havingthe appropriate electrical properties for forming a proximity couplinginterconnect. In some embodiments, the proximity coupling interconnect135 can be a capacitive coupling interconnect, in which case the firstconductive pad 137 and the second conductive pad 139 each act as acapacitive plate. In such a capacitive coupling interconnect 135, theelectric field between the first capacitive plate and the secondcapacitive plate serves as the medium through which signals aretransmitted between the first die 109 and the second die 123. In otherembodiments, the proximity coupling interconnect 135 can be an inductivecoupling interconnect, in which case the first conductive pad 137 andthe second conductive pad 139 can include conductive coil patterns toinduce magnetic flux between the first conductive pad 137 and the secondconductive pad 139. In some embodiments, capacitive couplinginterconnects and inductive coupling interconnects can both be used asproximity coupling interconnects between the first die 109 and thesecond die 123. The gap height H can significantly influence theperformance of the proximity coupling interconnect 135. In someembodiments, the gap height H can be between about 1 micron and about 10microns. In some embodiments, the gap height H can be greater than 10microns. The desired gap height H can be varied based on manyparameters, such as the size and material of the first conductive pad137 and second conductive pad 139, the presence or absence of any fillmaterial in the gap 141, etc. In some embodiments, the thicknesses ofthe passivation layers 113 and 127 can be controlled to define the gapheight H. For example, in some embodiments the gap height H is definedby the sum of the thicknesses of the passivation layers 113 and 127 lessthe thicknesses of the first and second conductive pads 137 and 139. Inone embodiment, each passivation layer 113, 127 can have a thicknessthat extends about 5 microns beyond the respective conductive pads 137,139, resulting in a gap height H of about 10 microns. In someembodiments, the size of connectors 131 can define the gap height H. Forexample, a larger connector 131 may result in the second die 123—andtherefore the second conductive pad 139—achieving a position furtherfrom the first die 109 and the first conductive pad 137.

The use of proximity coupling interconnects provides several advantagesover direct bonding. For example, the conductive pads used for proximitycoupling interconnects can often be significantly smaller than bond padsused for direct bonding such that arrays of proximity couplinginterconnects can have very fine pitches. The reduced footprint of theconductive pads also introduces tighter alignment tolerances to achieveeffective communication between opposing conductive pads and to reducecross-talk between adjacent conductive pads. The assembly 100illustrated in FIGS. 1A-C can achieve precise alignment between thefirst conductive pad 137 and the second conductive pad 139 because ofthe interaction between the connectors 131 and the second die 123. Forexample, the alignment pads 133 can be formed at precise locations onthe upper surface 103 of the substrate 101 using conventionalsemiconductor processing techniques. Based on the position of thealignment pads 133, the first die 109 can be placed at a predefinedposition with respect to the alignment pads 133 such that the firstconductive pad 137 is positioned precisely at a known location relativeto the alignment pads 133. The second die 123 can be placed, but notfixedly attached, using a flip-chip technique such that the connectors131 are substantially aligned between the alignment pads 133 on thesubstrate 101 and the bond pads 129 on the second die 123. At thispoint, the second die 123 is free to move laterally because it is notyet fixedly attached. This level of alignment can be achieved usingconventional flip-chip approach, as the alignment pads 133 and bond pads129 can be larger than the first conductive pad 137 and the secondconductive pad 139 of the proximity coupling interconnect 135. Uponreflow, the connectors 131 liquefy and the surface tension of theconnectors 131 automatically refines the lateral position and/orelevation of the unattached second die 123 such that the bond pads 129are more precisely aligned with the alignment pads 133. This in turnprecisely aligns the first conductive pad 137 and the second conductivepad 139. The spacing between the first conductive pad 137 and the secondconductive pad 139 can be based, at least in part, on the volume of theconnectors 131.

FIGS. 2A-2G are cross-sectional views illustrating a method ofmanufacturing a semiconductor die assembly in accordance withembodiments of the present technology. Like reference numbers refer tolike components in FIGS. 1-2G. Referring to FIG. 2A, contact pads 114(only one shown) and alignment pads 133 can be formed or deposited onthe upper surface 103 of the substrate 101. FIG. 2B illustrates theassembly after the first die 109 has been mounted onto the upper surface103 of the substrate 101. In the illustrated embodiment, the first die109 includes the passivation layer 113 and the first conductive pad 137before the first die 109 is mounted to the substrate 101. The first die109 can be mounted using conventional techniques such as tape, films, oradhesive paste such that the first die 109 is accurately placed at apredetermined position with respect to the alignment pads 133. Therelative position of the alignment pads 133 and the first conductive pad137 contributes to ultimate alignment of the proximity couplinginterconnect, as described in more detail below.

Referring now to FIG. 2C, the spacer 117 can be mounted onto thesubstrate 101 at a position spaced laterally from the first die 109. Asillustrated, the alignment pads 133 are disposed between the first die109 and the spacer 117. In this embodiment, the passivation layer 121has been disposed over the surface of the spacer 117 before the spacer117 is mounted to the substrate 101. The overall height of the first die109 and the spacer 117 can be the same. FIG. 2D shows the system afterthe second die 123 has been disposed over the first die 109, and thespacer 117. The second die 123 includes a coupling face 125 that facesthe first die 109, a passivation layer 127, bond pads 129 and at leastone second conductive pad 139. Connectors 131 are coupled to the bondpads 129 to provide electrical and mechanical connection between thesecond die 123 and the substrate 101. The second conductive pad 139 isconfigured to form a proximity coupling interconnect along with thefirst conductive pad 137.

As illustrated in FIG. 2D, the second die 123 need not be preciselyaligned with the first die 109, such that the first conductive pad 137is not precisely aligned with the second conductive pad 139. Referringto FIG. 2E, the entire assembly can be heated to reflow the connectors131. In this process, the surface tension of the liquefied connectors131 automatically pulls the second die 123 into alignment with respectto the alignment pads 133. As a result, the first conductive pad 137 isalso aligned with the second conductive pad 139 to form the proximitycoupling interconnect 135. As noted above, the proximity couplinginterconnect 135 can be a capacitive coupling interconnect or aninductive coupling interconnect. In some embodiments, the height of thegap between the first conductive pad 137 and the second conductive pad139 can be defined at least in part by the thickness of the passivationlayer 113 on the first die 109, the thickness of the passivation layer121 on the spacer 117, and the thickness of the passivation layer 127 onthe second die 123. In some embodiments, the height of the gap betweenthe first conductive pad 137 and the second conductive pad 139 can bedefined at least in part by the size of the connectors 131. Althoughonly one proximity coupling interconnect 135 is shown in FIG. 2E, inpractice the first die 109 has a plurality of first conductive pads 137and the second die 123 has a plurality of second conductive pads 139arranged in corresponding arrays. As such, the precise alignment causedby reflowing the connectors 131 to accurately position the second die123 enables fine pitch arrays of small conductive pads 137, 139 to forma fine pitch array of proximity coupling interconnects 135.

Referring to FIG. 2F, the first die 109 is electrically coupled to thesubstrate 101 via wirebonds 115 (only one shown) attached to contactpads 114 (only one shown). FIG. 2G shows the assembly after a thermallid 241 has been mounted to the substrate 101 to encapsulate theassembly, including the first die 109, the second die 123, and thespacer 117. In some embodiments, a thermal interface material or othermaterial having a low coefficient of thermal expansion can be dispensedover the substrate 101 prior to attachment of the thermal lid 241. Insome embodiments, the space between the thermal lid 241 and thesubstrate 101 can be backfilled with a material such as a thermalinterface material or other material having a low coefficient of thermalexpansion.

FIG. 3 illustrates a top plan view of another embodiment of asemiconductor die assembly 300 in accordance with the presenttechnology. The assembly 300 includes a substrate 301 and a plurality offirst semiconductor dies 343 a-d (collectively dies 343) mounted on itssurface. The first semiconductor dies 343 can be, for example, DRAM diesor other memory dies, and they can be mounted to the substrate 301 usingconventional techniques such as adhesive paste, tape, or films. A secondsemiconductor die 323 is mounted over a portion of each of the firstsemiconductor dies 343 a-d. The second semiconductor die 323 can be, forexample, a logic die mounted into position using a flip-chip techniqueover connectors 331 which couple the second semiconductor die 323 to thesubstrate 301. A plurality of proximity coupling interconnects 335 canbe formed between the second semiconductor die 323 and each of the firstsemiconductor dies 343 a-d. The proximity coupling interconnects 335 canhave conductive pads spaced apart by a gap similar to those describedabove with respect to FIGS. 1A-2H. In some embodiments, one or more ofthe first semiconductor dies 343 a-d can be replaced with a spacer.Although three proximity coupling interconnects 335 are shown betweenthe second semiconductor die 323 and each of the first semiconductordies 343 a-d, most devices have large number (e.g., in the tens,hundreds, or thousands) of proximity coupling interconnects between onesemiconductor die and another. Similarly, although four connectors 331are illustrated, most devices have a larger array of connectors.

FIG. 4 illustrates a cross-sectional view of another embodiment of asemiconductor die assembly 400 in accordance with the presenttechnology. The assembly 400 includes a substrate 401 having an uppersurface 403 and a lower surface 405, and a plurality of solder bumps 407disposed on the lower surface 405 for mounting the assembly 400 to aprinted circuit board or other chip (not shown). The assembly 400 alsohas a plurality of first semiconductor dies 409 a-b disposed over theupper surface 403 of the substrate 401, and the one first die 409 a isspaced laterally apart from the other first die 409 b. The firstsemiconductor dies 409 a-b include a coupling face 411, a passivationlayer 413 over the coupling face 411, and a first conductive pad 437 onthe coupling face. In this embodiment, the assembly 400 also has asecond semiconductor die 423 disposed over the first semiconductor dies409 a-b. The second semiconductor die 423 includes a coupling face 425that faces the first semiconductor dies 409 a-b as well as the substrate401, a passivation layer 427 disposed on the coupling face 425, and aplurality of bond pads 429 disposed on the coupling face 425. Theassembly 400 can have connectors 431 coupled to each of the bond pads429 on the coupling face 425 of the second semiconductor die 423.

The assembly 400 also includes a plurality of proximity couplinginterconnects 435 that each have a first conductive pad 437 and a secondconductive pad 439. The first conductive pads 437 are opened through thepassivation layers 413 on the first semiconductor dies 409 a-b, and thesecond conductive pads 439 are opened through the passivation layer 427on the second semiconductor die 423. In some embodiments, the firstconductive pads 437 and the second conductive pads 439 can each be sizedbetween about 5 microns by about 5 microns to about 25 microns by 25microns. In some embodiments, the first conductive pads 437 and thesecond conductive pads 439 can each be sized at less than about 5microns by about 5 microns, or greater than about 25 microns by about 25microns.

The above features of the embodiment illustrated in FIG. 4 can besubstantially similar to those shown in FIGS. 1A-C. However, as shown inFIG. 4, the first semiconductor dies 409 a-b and the connectors 431 areall not connected directly to the substrate 401. Rather, they arestacked over additional semiconductor dies or spacers havingthrough-silicon vias. For example, the assembly 400 can have thirdsemiconductor dies 443 a-b disposed over the upper surface 403 of thesubstrate 401. The first semiconductor die 409 a is stacked over thethird semiconductor die 443 a, the first semiconductor die 409 b isstacked over the third semiconductor die 443 b, and through-silicon vias445 electrically couple the first semiconductor dies 409 a-b and/or thethird semiconductor dies 443 a-b to each other through interconnects 449and through-silicon vias 447. The through-silicon vis 445 alsoelectrically couple the third semiconductor dies 443 a-b to thesubstrate 401.

The assembly 400 can further include a fourth semiconductor die 459 orspacer disposed over the upper surface 403 of the substrate 401 at aposition laterally between the third semiconductor dies 443 a-b. Thefourth semiconductor die 459 can include through-silicon vias 461 thatare electrically coupled to alignment pads 433, which are coupled tocorresponding bond pads 429 of the second semiconductor die 423 viaconnectors 431.

The assembly 400 can provide precise alignment between the firstconductive pads 437 and the second conductive pads 439 while takingadvantage of the benefits of vertical stacking. Alignment can beachieved due to the interaction between the connectors 431 and thesecond semiconductor die 423. The fourth semiconductor die 459 can beplaced on the upper surface 403 of the substrate 401 using conventionalsemiconductor processing techniques. Based on the position of the fourthsemiconductor die 459, and in particular the alignment pads 433, thethird semiconductor dies 443 a-b can be placed at predefined positionswith respect to the alignment pads 433 of the fourth semiconductor die459. The first semiconductor dies 409 a-b can be stacked over the thirdsemiconductor dies 443 a-b using conventional techniques, and can bealigned such that the first conductive pads 437 are in predeterminedpositions with respect to the alignment pads 433 of the fourthsemiconductor die 459. The second semiconductor die 423 can then beplaced using a flip-chip technique such that the connectors 431 arealigned between the alignment pads 433 on the fourth semiconductor die459 and the bond pads 429 on the second semiconductor die 423. Thislevel of alignment can be achieved using conventional flip-chipapproach, as the alignment pads 433 and the bond pads 429 can be largerthan the first conductive pads 437 and the second conductive pads 439 ofthe proximity coupling interconnect 435. Upon reflow, the connectors 431liquefy and the surface tension automatically causes alignment betweenthe bond pads 429 and the alignment pads 433, which correspondinglyresults in alignment of the first conductive pads 437 and the secondconductive pads 439.

Any one of the semiconductor dies described above with reference toFIGS. 1A-4 can be incorporated into any of a myriad of larger and/ormore complex systems, a representative example of which is system 500shown schematically in FIG. 5. The system 500 can include asemiconductor die assembly 510, a power source 520, a driver 530, aprocessor 540, and/or other subsystems or components 550. Thesemiconductor die assembly 510 can include features generally similar tothose of the stacked semiconductor die assemblies described above, andcan therefore include a plurality of proximity coupling interconnectshaving improved electrical performance. The resulting system 500 canperform any of a wide variety of functions, such as memory storage, dataprocessing, and/or other suitable functions. Accordingly, representativesystems 500 can include, without limitation, hand-held devices (e.g.,mobile phones, tablets, digital readers, and digital audio players),computers, and appliances. Components of the system 500 may be housed ina single unit or distributed over multiple, interconnected units (e.g.,through a communications network). The components of the system 500 canalso include remote devices and any of a wide variety ofcomputer-readable media.

From the foregoing, it will be appreciated that specific embodiments ofthe invention have been described herein for purposes of illustration,but that various modifications may be made without deviating from thedisclosure. Certain aspects of the new technology described in thecontext of particular embodiments may also be combined or eliminated inother embodiments. Moreover, although advantages associated with certainembodiments of the new technology have been described in the context ofthose embodiments, other embodiments may also exhibit such advantagesand not all embodiments need necessarily exhibit such advantages to fallwithin the scope of the technology. Accordingly, the disclosure andassociated technology can encompass other embodiments not expresslyshown or described herein.

We claim:
 1. A method for manufacturing a semiconductor packageassembly, the method comprising: disposing a first semiconductor dieadjacent to a substrate having bond pads, the first semiconductor diehaving a first coupling face that faces away from the substrate;disposing a second semiconductor die adjacent to the substrate andspaced laterally apart from the first semiconductor die, the secondsemiconductor die having a second coupling face that faces away from thesubstrate, wherein the second semiconductor die is a dummy die; andstacking a third semiconductor die over the first semiconductor die andthe second semiconductor die, the third semiconductor die having a thirdcoupling face and bond pads at the third coupling face, the thirdcoupling face facing but not contacting the first coupling face andfacing but not contacting the second coupling face; wherein stacking thethird semiconductor die includes aligning a third conductive pad on thethird coupling face with a first conductive pad on the first couplingface to form a first proximity coupling interconnect, wherein the thirdconductive pad is spaced from the first conductive pad by a first gapdistance, wherein no proximity coupling interconnect is formed betweenthe third semiconductor die and the second semiconductor die, whereinone or more electrical connectors extend between a corresponding one ofthe bond pads of the third semiconductor die and a corresponding one ofthe bond pads of the substrate and are positioned between the firstsemiconductor die and the second semiconductor die; and wherein anopening vertically extends through a first passivation layer formed onthe first coupling face and a third passivation layer formed on thethird coupling face and extends between a surface of the firstconductive pad and a surface of the third conductive pad, wherein thesum of a height of the opening and a thickness of the first and thirdconductive pads equals the sum of a thickness of the first passivationlayer and a thickness of the third passivation layer.
 2. The method ofclaim 1, further comprising: positioning the one or more electricalconnectors laterally apart from the first proximity couplinginterconnect.
 3. The method of claim 2, wherein the position of theelectrical connector defines the alignment of the first conductive padand the third conductive pad.
 4. The method of claim 1, wherein thefirst and third passivation layers define the first gap distance betweenthe first conductive pad and the third conductive pad.
 5. The method ofclaim 1, wherein the first proximity coupling interconnect comprises acapacitive coupling interconnect or an inductive coupling interconnect.6. The method of claim 1, wherein the first gap distance is about 1microns to about 10 microns.
 7. The method of claim 1, wherein the firstsemiconductor die comprises a memory die.
 8. The method of claim 1,wherein the third semiconductor die comprises a logic die.
 9. The methodof claim 1, further comprising coupling a thermal lid to the substrate,the thermal lid enclosing the first semiconductor die, the secondsemiconductor die and the third semiconductor die.
 10. The method ofclaim 9, further comprising disposing a thermal fill material betweenthe thermal lid and the first semiconductor die, the secondsemiconductor die and the third semiconductor die.
 11. The method ofclaim 1, further comprising disposing an underfill material between thethird semiconductor die and the substrate.
 12. The method of claim 1,wherein the third semiconductor die extends over at least the bond padson the substrate.
 13. A method of manufacturing a semiconductor packageassembly, the method comprising: disposing a third semiconductor dieover a first semiconductor die and a second semiconductor die, whereinthe third semiconductor die has a third coupling face having a firstportion that overlaps but does not contact a first coupling face of thefirst semiconductor die and a second portion that overlaps but does notcontact a second coupling face of the second semiconductor die, andwherein the second semiconductor die is a dummy die; and aligning afirst pad on the first coupling face and a third pad on the thirdcoupling face to form a first proximity coupling interconnect betweenthe first semiconductor die and the third semiconductor die, wherein thefirst pad is spaced apart from the third pad by a first open space;wherein no proximity coupling interconnect is formed between the thirdsemiconductor die and the second semiconductor die, wherein a spacingstructure projecting from a third portion of the third coupling facethat does not overlap the first coupling face or the second couplingface defines a first gap between the first pad and the third pad; andwherein an opening vertically extends through a first passivation layerformed on the first coupling face and a third passivation layer formedon the third coupling face and extends between a surface of the firstpad and a surface of the third pad, wherein the sum of a height of theopening and a thickness of the first and third pads equals the sum of athickness of the first passivation layer and a thickness of the thirdpassivation layer.
 14. The semiconductor package assembly of claim 13,wherein the first proximity coupling interconnect comprises a capacitivecoupling interconnect or an inductive coupling interconnect.
 15. Thesemiconductor package assembly of claim 13, wherein the spacingstructure comprises a solder interconnect spaced laterally apart fromthe first proximity coupling interconnect and extending between thethird portion of the third coupling face and a substrate.
 16. Thesemiconductor package assembly of claim 13, wherein first pad is spacedfrom the third pad by a distance from about 1 microns to about 10microns.